The invention relates to an automatically controlled washing machine with a detergent-solution circulating system in which detergent solution is discharged by means of a pump at the bottom of a washing handling space and is fed back to the handling space via a pipeline above the washing located in the handling space, which washing machine is also connected to a fresh-water supply line which can be opened and closed by a valve which is controllable by a sensor device suitable for establishing a volumetric flow present in the pumping direction of the pump.
Such a washing machine is known from DE-A-43 32 225. In the case of this washing machine, a detergent-solution circulating system is connected at the bottom of the tub in order for washing-detergent or rinsing solution to be constantly flowing through the washing located in the washing drum. This circulating system comprises a pipeline, along which a detergent-solution pump and a sensor device are arranged. The presence of a flow in the pipeline is sensed by the sensor device. Depending on the presence or absence of a flow in the pipeline, the sensor device emits a corresponding signal to the valve arranged along the fresh-water supply line, whereby the fresh-water supply is either introduced or shut off. In this way, the washing machine is constantly supplied only with the amount of water absolutely necessary.
The invention is based on the object of developing a washing machine of the type described at the beginning in such a way that the control of the fresh-water supply can take place as far as possible with sensor elements that are already on the washing machine in any case.
The set object is achieved according to the invention by a body which can be actuated by the volumetric flow prevailing in the pipeline being arranged along the pipeline and, depending on the presence or absence of volumetric flow, protruding into or releasing the measuring section of a turbidity sensor, by which turbidity sensor the valve is controlled so as to assume its opening or closed position. Consequently, just a simple mechanical part need be installed in the pipeline, whereas the turbidity sensor present in any case for measuring the turbidity of the rinsing water is used for the more complex sensing task.
According to a further refinement of the invention, the body is designed as a float and is arranged in a vertically extending region of the pipeline. In the case of such an arrangement, the float assumes its position of rest of its own accord, on account of gravity. consequently, no separate means are required for returning the float to its position of rest.
As a result of the fact that the float is design ed in the manner of a valve disk provided with a stem, the stem protruding into the measuring section of the turbidity sensor when the float is in the position of rest and the valve disk bearing against a valve seat, the pipeline is completely shut off when the float is in the position of rest. Consequently, the occurrence of even a very small volumetric flow already leads to the float being adjusted. This makes the device very sensitive.
A separate valve seat in the pipeline can be avoided by the circumferential rim of the valve disk having a conically flared profile and the pipeline being in the same way of a conical design, at least in the region of the position of rest of the float.
In the pipeline there is expediently also provided a stop which limits the adjusting path of the float and the position of which is chosen such that when the float is bearing against the stop the stem completely releases the measuring section of the turbidity sensor.